Synthesis of amine-functionalized ZIF-8 with 3-amino-1,2,4-triazole by postsynthetic modification for efficient CO2-selective adsorbents and beyond

Abstract

The facile tuning of the gate size and the chemical functionahzation of zeolitic imidazolate frameworks (ZIFs) have been considered efficient strategies for various potential applications including gas membranes, sensors, and catalysts. Herein, we demonstrate the synthesis of amine-functionahzed ZIF-8 (ZIF8-A) with 3-amino-1,2,4-triazole (Atz) by postsynthetic modification (PSM) towards two objectives: (1) CO2 selective adsorption by a combination of chemical interactions and controlled gate sizes and (2) potential for further chemical modifications. The acquired ZIF8-A substantially enhanced CO2/N-2 and CO2/CH4 selectivity at 35 degrees C compared to ZIF-8 since the Atz conversion enhanced chemical interactions with CO2 due to the introduction of amine moieties while reducing both the surface area and pore volume. The gate size control of ZIF-8 by the replacement of Atz was thoroughly investigated by extensive transport experiments and density functional theory (DFT)based computational simulations. In addition, the vinykfunctionahzed ZIF-8, another versatile starting material, was successfully prepared by further chemical modifications of ZIF8-A with either methacryhc anhydride or gEycidyE methacryEate through nucleophllic substitution reactions. As such, we believe that our current work can provide promising platforms for designing ZIF-based materials with versatile properties including precise control of the gate size and the incorporation of various functional groups.